The motor vehicle lock in question is assigned to a motor vehicle door arrangement which comprises at least a motor vehicle door. The expression “motor vehicle door” is to be understood in a broad sense. It includes in particular side doors, back doors, lift gates, trunk lids or engine hoods. Such a motor vehicle door may generally be designed as a sliding door as well.
The crash safety plays an important role for today's motor vehicle locks. It is of particular importance that neither crash induced acceleration nor crash induced deformation leads to an unintended opening of the motor vehicle door which the motor vehicle door lock is assigned to. The focus of the present application is to prevent an unintended opening of the motor vehicle door based on crash induced deformation, for example a crash induced deformation of a door body shell.
The known motor vehicle lock (WO 2012/130201 A2), which is the starting point for the invention, is provided with a crash mechanism which prevents a crash induced and unintended opening of the motor vehicle door. In case of a crash induced deformation of a door body shell the respective section of the door body shell comes into engagement with the crash mechanism which leads to the crash mechanism being brought from a normal condition into a crash condition. The crash mechanism comprises a crash element which is actually a blocking element for a pawl actuation lever. When the crash mechanism is in its crash condition, the actuation of the pawl actuation lever is being blocked by the crash element.
The known motor vehicle lock is generally advantageous as it reacts to crash induced deformation, and not to crash induced acceleration. With this it is possible to react to crash induced situations that require the prevention of opening of the motor vehicle door but that, however, do not show high crash induced accelerations.
A disadvantage of the known motor vehicle lock is the difficult design of the drive train that allows opening the motor vehicle door by an outer door handle or the like. As the crash mechanism of the known motor vehicle lock reacts to the crash induced deformation by blocking part of the drive train, the crash induced actuation forces on the outer door handle are being transferred into the motor vehicle lock. In order to prevent non-reproducible breakage of the drive train, this drive train has to be designed for correspondingly high actuation forces. As noted above, however, those high crash induced actuation forces may not even be present during the above noted, crash induced deformation such that in the end for many crash situations the drive train would be oversized.